myiframe are not load data on first time click ,but again

Question

my iframe are not load data on first time click ,but again i click it load database why

 

This is my code please help me

protected void TotalComment_Click(object sender, EventArgs e)
{
HtmlControl frame1 = (HtmlControl)FindControl("irm1");
string Id = ((Button)sender).CommandArgument;
frame1.Attributes.Add("src", "BlogPost.aspx?BlogId="+Id);

}